package com.abc.util;

import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

/**
 * RSA加解密工具类，实现公钥加密私钥解密和私钥解密公钥解密
 */
public class RSAUtils {

    private static final String src = "abcdefghijklmnopqrstuvwxyz";

    public static void main(String[] args) throws Exception {
//        System.out.println("\n");
//        RSAKeyPair keyPair = generateKeyPair();
//        System.out.println("公钥：" + keyPair.getPublicKey());
//        System.out.println("私钥：" + keyPair.getPrivateKey());
//        System.out.println("\n");
//        test1(keyPair, src);
//        System.out.println("\n");
//        test2(keyPair, src);
//        System.out.println("\n");

//        String s1 = encryptByPublicKey("MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCg3VX1svV1hW8oLnNUOhtpTH+2ogJkaveLRDcN46RkdoX6WCyFFVmPJjk5mFiwvTVuY7Y3WaK5GP66c27EsdU5VGbYJxedz1nSgx1Cr9bDK3FZRNwN0+0qsxQcTEAcidQqMntZT3ufxsLL+C83ee3otteU7x9bCT03BrMuB2RmhwIDAQAB", "abcdefg");
//        System.out.println(s1);
        String s = decryptByPrivateKey("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", "PO+MKhOMDGogYE8/1CMzvjU4kdvUwnBJi6KMVlFYQ0Gz853tbATy35owzsvBhw/2IZCtjOM7hU+YUT9WlvCN1biz2wfiFoJE/Frsxv0Y6QZP/nJkUi5MlN5WilY7p9/BmK3px6iHwiONGw7A76+ATJN49s0KJRKquasmEkmhSY8=");
        System.out.println(s);

    }

    /**
     * 公钥加密私钥解密
     */
    private static void test1(RSAKeyPair keyPair, String source) throws Exception {
        System.out.println("***************** 公钥加密私钥解密开始 *****************");
        String text1 = encryptByPublicKey(keyPair.getPublicKey(), source);
        String text2 = decryptByPrivateKey(keyPair.getPrivateKey(), text1);
        System.out.println("加密前：" + source);
        System.out.println("加密后：" + text1);
        System.out.println("解密后：" + text2);
        if (source.equals(text2)) {
            System.out.println("解密字符串和原始字符串一致，解密成功");
        } else {
            System.out.println("解密字符串和原始字符串不一致，解密失败");
        }
        System.out.println("***************** 公钥加密私钥解密结束 *****************");
    }

    /**
     * 私钥加密公钥解密
     *
     * @throws Exception
     */
    private static void test2(RSAKeyPair keyPair, String source) throws Exception {
        System.out.println("***************** 私钥加密公钥解密开始 *****************");
        String text1 = encryptByPrivateKey(keyPair.getPrivateKey(), source);
        String text2 = decryptByPublicKey(keyPair.getPublicKey(), text1);
        System.out.println("加密前：" + source);
        System.out.println("加密后：" + text1);
        System.out.println("解密后：" + text2);
        if (source.equals(text2)) {
            System.out.println("解密字符串和原始字符串一致，解密成功");
        } else {
            System.out.println("解密字符串和原始字符串不一致，解密失败");
        }
        System.out.println("***************** 私钥加密公钥解密结束 *****************");
    }

    /**
     * 公钥解密
     *
     * @param publicKeyText
     * @param text
     * @return
     * @throws Exception
     */
    public static String decryptByPublicKey(String publicKeyText, String text) throws Exception {
        X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(Base64.decodeBase64(publicKeyText));
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
        byte[] result = cipher.doFinal(Base64.decodeBase64(text));
        return new String(result);
    }

    /**
     * 私钥加密
     *
     * @param privateKeyText
     * @param text
     * @return
     * @throws Exception
     */
    public static String encryptByPrivateKey(String privateKeyText, String text) throws Exception {
        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyText));
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        byte[] result = cipher.doFinal(text.getBytes());
        return Base64.encodeBase64String(result);
    }

    /**
     * 私钥解密
     *
     * @param privateKeyText
     * @param text
     * @return
     * @throws Exception
     */
    public static String decryptByPrivateKey(String privateKeyText, String text) throws Exception {
        PKCS8EncodedKeySpec pkcs8EncodedKeySpec5 = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyText));
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec5);
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        byte[] result = cipher.doFinal(Base64.decodeBase64(text));
        return new String(result);
    }

    /**
     * 公钥加密
     *
     * @param publicKeyText
     * @param text
     * @return
     */
    public static String encryptByPublicKey(String publicKeyText, String text) throws Exception {
        X509EncodedKeySpec x509EncodedKeySpec2 = new X509EncodedKeySpec(Base64.decodeBase64(publicKeyText));
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec2);
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        byte[] result = cipher.doFinal(text.getBytes());
        return Base64.encodeBase64String(result);
    }

    /**
     * 构建RSA密钥对
     *
     * @return
     * @throws NoSuchAlgorithmException
     */
    public static RSAKeyPair generateKeyPair() throws NoSuchAlgorithmException {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(1024);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
        String publicKeyString = Base64.encodeBase64String(rsaPublicKey.getEncoded());
        String privateKeyString = Base64.encodeBase64String(rsaPrivateKey.getEncoded());
        RSAKeyPair rsaKeyPair = new RSAKeyPair(publicKeyString, privateKeyString);
        return rsaKeyPair;
    }


    /**
     * RSA密钥对对象
     */
    public static class RSAKeyPair {

        private String publicKey;
        private String privateKey;

        public RSAKeyPair(String publicKey, String privateKey) {
            this.publicKey = publicKey;
            this.privateKey = privateKey;
        }

        public String getPublicKey() {
            return publicKey;
        }

        public String getPrivateKey() {
            return privateKey;
        }

    }

}